The present invention, in some embodiments thereof, relates to an antenna system fabrication and, more particularly, but not exclusively, to an antenna system having two end-fire antenna elements facing each other.
Optical radiation is typically manipulated by redirecting its wave front with lenses and mirrors, which are subject to diffraction. As a consequence of this diffraction, optical fields cannot be localized to dimensions which are much less than the optical wavelength.
Nano-antennas provide a solution as they can efficiently couple the energy of free-space radiation to a confined region of sub-wavelength size. Although the use of radiofrequency (RF) antennas is widespread, such as in the radio- and microwave regimes, they are an emerging technology at optical frequencies.
Heretofore, there have seen a considerable amount of work devoted to nano-antennas for the IR and optical frequencies [Crozier et al., J. Appl. Phys., 94, 4632 (2003); Derkacs et al., Appl. Phys. Lett., 89, 093103 (2006); Kuhn et al., Phys. Rev. Lett., 96, 017402 (2006); and Bouhelier et al.]. In terms of performances, conventional nano-antennas having a broad frequency band of operation are characterized by low radiation efficiency [Alù et al., Phys. Rev. Lett., 101, 043901 (2008)].